Synthesis of WO₃ nanoparticles using a biopolymer as a template for electrocatalytic hydrogen evolution

Tungsten trioxide nanoparticles were prepared by a simple approach using chitosan biopolymer as a template. These nanoparticles were characterized using x-ray diffraction, Raman spectroscopy, transmission electron microscopy and high resolution transmission electron microscopy. The average size of the WO ₃ nanoparticles is 42 nm, and they intercalate a larger amount of hydrogen than tungsten trioxide, which is prepared without chitosan. The materials are tested for their electrocatalytic hydrogen evolution in a sulfuric acid medium, where WO₃ nanoparticles show a fourfold higher activity than bulk tungsten trioxide.